高气压环境脉冲MAG焊气体混合比对焊接稳定性的影响

Influence of gas mixing ratio in stability of welding on hyperbaric pulsed MAG welding

分析了压力环境下气体混合比对脉冲MAG焊飞溅率及焊缝熔池形状的影响.结果表明,压力环境下相同比例的保护气体在流速不变的情况下,起活性作用的气体组分相对较多,电弧弧柱紊乱加剧,飞溅剧烈,焊接过程极不稳定.为获得高气压环境下稳定的焊接过程,减小飞溅率,通过提高混合气体配比中氩气体积分数来降低活性气体造成的能量损失,从而减少飞溅.防止缺陷的产生.综合考虑飞溅率、熔滴过渡稳定性及焊缝熔池形状等因素,在0.3 MPa环境压力下使用90%Ar+10%CO2混合气进行焊接可获得最佳的焊接效果.气体配比的有效调节对于提高高气压环境下脉冲MAG焊焊接过程稳定性和焊接质量具有显著作用.

The effects of gas mixture ratio in hyperbaric environment on pulsed MAG welding splash ratio and the shape of weld pool were analysed. Experimental results showed that more active gas made the weld arc instable,the spatter increase and the welding process extremely unstable in the same condition. In order to obtain the stable welding process and reduce the rate of spatter in hyperbaric environment and then prevent the formation of defects,the ratio of Ar was increased to reduce energy loss. Taking into consideration the influence of the splash ratio,the stability of droplet and the shape of weld pool,experiments results showed that 90% Ar + 10% CO2 gas mixtures in 0. 3MPa can make the best welding quality. The effective control of gas mixture ratio has a significant effect on the stability of pulse MAG welding in hyperbaric environment.